> Addex Receives $5 Million Upfront, Potential Milestones of $330 Million and Tiered Royalties up to Double Digit

> Addex Receives $4 Million Research Funding over 2 years and Retains Rights to Advance Additional GABAB PAMs in CMT1A Neuropathy

Addex Therapeutics (SIX: ADXN) announced today the signing of a licensing and collaboration agreement with Indivior PLC (LON: INDV) for global development and commercialization of ADX71441 for the treatment of addiction. ADX71441 is a potent, selective positive allosteric modulator (PAM) that potentiates GABA responses at the GABAB receptor. In addition, Indivior will fund a research program at Addex to discover additional GABAB PAM compounds.

Under the terms of the agreement, Addex will receive $5 million upfront, $4 million of committed research funding over the next two years, $330 million of potential development, regulatory and commercialization milestones and tiered royalties up to double-digit. Addex retains the right to select compounds from the research collaboration for certain indications outside addiction, including Charcot-Marie-Tooth type 1a neuropathy (CMT1A).

“As a world leader in developing and commercializing treatments for addiction, Indivior is the perfect partner to continue development of ADX71441 which has shown potential in several preclinical models of addiction,” commented Tim Dyer, CEO at Addex. “This agreement is part of our ongoing strategy to secure resources to advance certain assets of our broad allosteric modulator pipeline with leading players in key markets.”

“The development of ADX71441 illustrates the power of Addex’s allosteric technology to discover new small molecules that are able to modulate precisely the activity of a receptor so that beneficial attributes are accentuated,” said Robert Lütjens, PhD, Head of Discovery at Addex. “We are excited by the research program as it provides us with the opportunity to explore further the utility of GABAB PAM, a well validated therapeutic target.”

About GABAB Activation and ADX71441

Activation of gamma-aminobutyric acid subtype B (GABAB) receptor, a Family C class of GPCR, is clinically & commercially validated. The generic GABAB receptor agonist, baclofen, is marketed for spasticity and some spinal cord injuries, and used for overactive bladder (OAB), but it is not commonly used due to variety of side effects of the drug and rapid clearance. ADX71441 is a potent, selective, first-in-class, oral positive allosteric modulator (PAM) that potentiates GABA responses at the GABAB receptor. It has demonstrated excellent preclinical efficacy and tolerability in several rodent models of pain, anxiety, addiction and OAB, as well as proven efficacy in a genetic model of Charcot-Marie-Tooth Type 1A disease (CMT1A). As a positive allosteric modulator, rather than an orthosteric agonist at the GABAB receptor like baclofen, ADX71441 only acts when the natural ligand (GABA) activates the receptor, therefore respects the physiological cycle of activation. It has been proposed that PAMs produce less adverse effects and lead to less tolerance than direct agonists (May and Christopoulos 2003; Langmead and Christopoulos 2006; Perdona et al. 2011; Urwyler 2011; Gjoni et al., 2008; Ahnaou et al). The US National Institute on Drug Abuse (NIDA, a division of National Institutes of Health (NIH)) has awarded Addex’s ADX71441 program a $5.3 million grant to support human studies.

About Indivior

Indivior is a global specialty pharmaceutical company with a 20-year legacy of leadership in patient advocacy and health policy while providing education on evidence-based treatment models that have revolutionized modern addiction treatment. The name is the fusion of the words individual and endeavour, and the tagline “Focus on you” makes the Company’s commitment clear. Indivior is dedicated to transforming addiction from a global human crisis to a recognized and treated chronic disease. Building on its global portfolio of opioid dependence treatments, Indivior has a strong pipeline of product candidates designed to both expand on its heritage in this category and address other chronic conditions and co-occurring disorders of addiction, including alcohol use disorder and schizophrenia. Headquartered in the United States in Richmond, VA, Indivior employs more than 900 individuals globally and its portfolio of products is available in over 40 countries worldwide. Visit www.indivior.com to learn more.

About Addex Therapeutics

Addex Therapeutics (www.addextherapeutics.com) is a biopharmaceutical company focused on the development of novel, orally available, small molecule allosteric modulators for neurological disorders. Allosteric modulators are an emerging class of small molecule drugs which have the potential to be more specific and confer significant therapeutic advantages over conventional "orthosteric" small molecule or biological drugs. Addex's allosteric modulator drug discovery platform targets receptors and other proteins that are recognized as essential for therapeutic intervention - the Addex pipeline was generated from this pioneering allosteric modulator drug discovery platform. Addex's lead drug candidate, dipraglurant (mGluR5 negative allosteric modulator or NAM) has successfully completed a Phase 2a POC in Parkinson's disease levodopa-induced dyskinesia (PD-LID), and is being prepared to enter registration trials for PD-LID with support from the Michael J. Fox Foundation for Parkinson's Research (MJFF). In parallel, dipraglurant's therapeutic use in dystonia is being investigated with support from the Dystonia Medical Research Foundation (DMRF). Addex's second clinical program, ADX71149 (mGluR2 positive allosteric modulator or PAM) is being developed in collaboration with Janssen Pharmaceuticals, Inc for epilepsy. In addition, ADX71441 (GABAB receptor PAM) program was awarded a $5.3 million grant by the US National Institute on Drug Abuse (NIDA, a division of National Institutes of Health (NIH)) to support human studies in cocaine addiction and has today been licensed to Indivior. Discovery programs include mGluR4PAM, mGluR7NAM, TrkBPAM and mGluR3NAM & PAM that are being advanced with the support of the MJFF and Swiss Commission for Innovation and Technology (CTI).

Disclaimer / Forward-looking statements: This communication does not constitute an offer or invitation to subscribe for or purchase any securities of Addex Therapeutics Ltd. This publication may contain certain forward-looking statements concerning the Company and its business. Such statements involve certain risks, uncertainties and other factors which could cause the actual results, financial condition, performance or achievements of the Company to be materially different from those expressed or implied by such statements. Readers should therefore not place undue reliance on these statements, particularly not in connection with any contract or investment decision. The Company disclaims any obligation to update these forward-looking statements.